Today enterprises operate in a constantly changing market, characterized by shorter and shorter product life cycles, an increased demand for flexibility and changing techniques and technologies. In order to control these factors of complexity, enterprise modeling has become a paramount topic, as attests the amount of work undertaken in this field since the middle 20th century. Although there have been efforts to handle automation, planning, optimization, a significant method is still lacking for addressing the human potential, its cognitive abilities and competences. The goal of this work is to present a new approach for enterprise modeling based on the competences falling under a philosophy of perenniality of the organization where the human is placed at the center of the processes. The suggested methodology is articulated around three principal elements: The development of a formalism for representing competence in order to integrate it in the entreprises competence based model; The development of a methodology for competence valorization which takes into account the suggested formalism; The taking into account of the challenges relating to the dynamic aspects of the model in particular for the creation of adequate teams and the problem of assigning actors to activities according to their competences. The proposed formalism is built, independently of any model, with the aim of making it operational at different levels of abstraction in order to be extended to an enterprise modeling approach based on the competences. An identification of the competences can thus be approached via this formalism by targeting one of the levels without necessarily taking into account the others, according to the desired degree of detail. The purpose of the methodology of competence valorization is to help the decision makers to understand, in term of competences, the stakes which have a deep impact on the strategic objectives of the company. These stakes are the identification of the true advantages and risks, following various points of view, in term of competences and resources mobilized in the processes of the enterprise. A step, which consists in identifying competences, is thus essential to allow an enterprise to ensure management in agreement with its strategic choices. The methodology used to evaluate the critical competences is based on techniques of fuzzy logic taking into account several criteria aggregated in indicators. Finally a methodology of management and competence assignment was developed in order to increase the ability of a company to quickly constitute the most adequate teams for an optimal management of day-to-day operations; as well as to identify assignment configurations of actors to activities according to their competences. Various studies were carried out in manufacturing companies to evaluate certain key points of this study. In an encouraging way, they confirm the coherence and the relevance of the proposed approach. These studies made it possible to test the suggested models and approaches but also to make recommendations for the development of a tool supporting the enterprise modeling approach based on the competences, in particular the module related to valorization. However additional studies on the scale of the whole company need to be carried out to guarantee the best impact of the presented work.